


A Little Too Casual

by Chozin_Yi



Category: Vocaloid
Genre: Anal Sex, Casual Sex, Cowgirl Position, Cunnilingus, Doggy Style, Dubious Consent, F/M, First Time Blow Jobs, Miku Gets a Cameo, Missionary Position, Nudity, Oral Sex, Sibling Incest, Twincest, casual nudity
Language: English
Status: Completed
Published: 2020-10-18
Updated: 2020-10-18
Packaged: 2021-03-08 18:14:28
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 2,010
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27091078
Author URL: https://archiveofourown.org/users/Chozin_Yi/pseuds/Chozin_Yi
Summary: When Rin and Len's idea for dealing with puberty leads to something they may be getting a little too comfortable with, it leads right into something else entirely.
Relationships: Kagamine Len/Kagamine Rin
Comments: 1
Kudos: 25





	A Little Too Casual

**Author's Note:**

> This story is also posted on FanFiction.

A Little Too Casual.

A Vocaloid One-Shot.

A Rin x Len Lemon.

Hey Everybody! Yes, I have returned with a new story! Before we begin, I just wanna say don't expect too much from this story and don't examine it too closely, it's just a simple, smutty, quickie. Hope you all enjoy!

Disclaimer Time!

1\. I do not own the Vocaloid program, nor the characters featured.

2\. This story is a lemon, meaning it contains naughty and sexual content.

3\. This story also contains Twincest.

Let the fun begin!

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You ever hear about how siblings, specifically twins, seem much more comfortable being naked around each other? Well, Rin and Len Kagamine happen to be a little TOO comfortable. 

Unknown to their best friends and other close acquaintances, Rin and Len are actually nudists. Only at home, but nudists nonetheless. 

When all home alone, Rin and Len would everything together as naked as the day they were born, whether it be eating meals together, watching TV, or playing video games, the blonde twins did everything without shame.

One thing though that would considered weird, even by other nudists, is that Len always has a hard on whenever he's in the same room as Rin. Rin however didn't think very much of it. Being the innocent soul she is, Rin just simply thought of it as Len having a natural bodily reaction, like any adolescent boy his age. It's easy to understand her train of thought, considering that she's the only naked girl he ever sees everyday.

That's just how it's been, ever since they hit puberty, hormones have been flying and it was just not a comfortable experience for either of them. By the time they both found out that one was trying to spy on the other due to their hormones, they struck a deal and decided to just forgo clothes whenever they were home to get it out of their system. It seemed to work, they liked checking each other out and felt much more comfortable, now feeling like that they had nothing to hide now.

However, it all changed one day, possibly for the better?

It had been a long day at school, and Rin and Len got home in a hurry, because they wanted to strip to their birthday suits and go skinny dipping in their backyard pool. They both entered their bedroom, tossed their backpacks onto the floor and began stripping down, tossing their shirts to the floor, kicking their shoes and socks off, and dropping their pants.

Rin moved on to her bra and tossed it away, leaving her perky A-Cups out for anyone to see before pulling her panties off, exposing her cute, petite butt, narrow hips, and clean shaven pussy.

Len pulled down his boxers and stared wide-eyed and Rin's nakedness, causing his teenage dick to stretch out and grow to full mast. Rin looked over and saw it, causing her giggle that her twin brother got hard again.

"C'mon Len! Let's go get wet!" She said, about to run out and head for the pool.

"Rin, wait!" Len stopped her, making her look at him weird.

"What's wrong?" She wondered.

"Just come here." He said, taking her hand and pulling her to her bed and pushing her down on her back.

"Len! What are you doing???" Rin said confused, Len getting on top of her.

With him on top of her body, she couldn't see exactly what he was doing, but felt him spread her legs and gently, but firmly hold her arms down.

"Len! What is going on-HAAAAAAHHHH!?" She suddenly gasps after feeling an insertion in her lower body.

She tries to push him up a little and looks down at herself in disbelief.

"Len, are you having sex with me?" She asks, looking up at his pleasure ridden face.

"Yeah, I'm sorry Rin, I couldn't help it! Just looking at your naked body everyday for so long just left me wanting more!" He admitted, adjusting himself a bit.

"But I'm your sister though, isn't that kinda weird?" She wondered before letting out a small, pleasured moan as she felt a nice tingle in her belly as Len adjusted himself.

"Yeah, but you're the only girl around who's willing to get naked with me!" He said, his eyes begging for pleasure.

"Well... I guess I should've known that being naked with a hormonal boy would kinda lead to this, plus... Mmmm!... It does feel REALLY good!" She moans a bit, A smile creeping on her face.

"So, can I...!?" He said excitedly, A big grin forming on his own face.

Rin nodded. "Hump me bro!"

Len needed no more prompting, and he started getting into a solid rhythm, humping Rin's pussy as he legs bobbed up and down at his sides. Rin blushed as she moaned loudly, making pleasured, high pitched squeaks while having a big smile and occasionally bitting her bottom lip as she experienced her first time having sex.

Len moaned as well, making loud, boyish cries of pleasure as his hips got going and clapped with Rin's body, her vagina tugging and pulling on his cock. His rhythm changed and he went faster, the bed rocking back and forth as his skinny butt bounced up and down and Rin's moaning got louder and squeakier.

"Ahhhh! Aahhhhhh! More! More Len! Keep going it's so good! Yaaahhhhhh! Myaaahhhhh! I want more!!!" She cried, her breathing getting more rapid and her toes curling.

Len kept up his pace and watched as Rin reached down to play with her clitty. Watching her play with herself as he fucked her turned him on so much.

"That's it Rin! Play with your clit!" He encouraged, A warm feeling pooling in his lower body and his balls rising in his sack.

Playing with herself as Len fucked her just made the whole experience feel perfect, her vagina was getting wetter and sharp jolts of pleasure rocked her body as she started bitting her lip again, until it felt like a knot in her belly was undone and her whole body erupted in pleasure.

"YEAAAAAAHHHHH LEEEN!!! THIS IS AMAAAAZIIIIIING!!!" She cried as her legs shot straight out and she pushed her pelvis hard into Len's, and her back arched.

When she calmed down, she looked up to see Len's red face tighten as she felt his hips jerk a little and he let out a pleasured sigh as she felt a hot, goopy, mess fill her insides, but it felt good!

Now that he was done, Len rolled over onto his back as his now flaccid penis slipped out of her, a small string of semen trailing behind.

They both tried to catch their breath, before looking over and smiling at each other.

"That was... nice Len, thank you!" Rin said happily.

"I should be thanking you Rin!" Len replied.

"So is this going to be a thing? First we pretty much become nudists, now we fuck too?" Rin wondered, twirling her hair with her finger.

"Do you want it to be a thing?" Len asked.

Rin blushed and giggled while hiding her eyes with her hands before peaking out. "Maybe." She teased.

She looked down at Len's lap, and reached down to touch his dick. She couldn't help but be intrigued as she fiddled with it, twirling it with her fingers, lightly tugging it, flopping it around.

"After only seeing it for a while, it's kinda cool actually touching it." She mentioned.

Len smiled in embarrassment as he watched her playing with his dick like a kid playing with a new toy. Still, it felt nice. He even started getting hard again.

Rin was in awe, now that she was touching it while it was hard. It felt so different now! Getting a crazy idea, she leaned down and took it into her mouth, sucking it like a lollipop.

Len gives a loud sigh as he watched Rin bobbing her head up and down his cock as she hummed in enjoyment.

"R-Rin, where did you learn this?" He asked curiously. He knew what a blowjob was, but wasn't sure if Rin knew as well.

She briefly took it out with a pop and looking up at her brother with bright eyes.

"No where really, I'm just kinda winging it." She replied before getting back to work.

Len watched his twin sister giving him head as he moaned a little and put a hand behind his head while putting the other on her butt, stroking her cute cheek.

After a little bit, Rin pulled her mouth off and climbed onto Len's lap, reaching down and holding up his cock.

"What are you doing Rin?" He asked.

"I wanna do it again!" She replied, sinking down onto his cock and crying out happily.

Now nice and comfortable, Rin started bouncing in her seat as Len and herself moaned a symphony, Len cupping her cute little butt in his hands, as Rin cooed in surprise.

"Oooh! You like to play with my butt?" She teased, giving him a sassy smile.

Her bouncing went faster as she started to really ride him, Len moaning loudly as he lightly kicked his leg in the air.

"Mmmmmm! Ohhhhh Len! Your dick feels great! Ohhhh yeeesss!" She moaned.

"Oooh Rin! Ride me harder! Ride me harder! Please! I'm almost there!" Len begged, feeling his climax approaching.

"Yes! Cum Len! Do it bro! Cum inside me!" Rin begged as well.

Len gasped and humped up with Rin as he came and creamed Rin's snatch, making her cum too.

Rin collapsed on top of him and they both held each other closely. 

"Wanna go swimming now?" She asked.

Since that day, whenever either of them were in the mood, they would run up to their bedroom, jump into whoever's bed and make love.

They needed little prompting, like one day, Len would be downstairs playing video games while was on her computer in their room, then Len would run in and say: "I got hard Rin!" leading to her gladly jumping into bed with him and hopping up and down on his boner until they both came.

One another particular day, Len wanted to try something new and had Rin all fours on the bed as he was about to fuck her ass. 

"Hurry up!~" She begged, hugging a pillow as she looked at him behind her.

"Hang on, I'm almost done!" He said, coating his dick in lotion before getting behind her and grabbing her hips.

He eased his way inside her, and Rin both smiled, and cringed feeling his cock invading her backdoor. Len moaned loudly as he fucked her tight ass, his waist clapping with her butt cheeks as Rin moaned while playing with her pussy.

This little act of Kagamine sodomy lasted for a little while until Len felt the rush and he pulled out, squirted white all over Rin's ass.

Len sighed as he released and when he was done, Rin rolled over onto her back, spreading her legs and rubbing her clitoris.

"That made me so horny! Care to help me Len?" She asked, winking at him.

He got the idea and leaned down and began to eat her out, Rin gasping and moaning as he toyed her clitty with his tongue, Rin holding his head down in her crotch.

Meanwhile outside, Hatsune Miku was walking her neighbor's dog and just happened to be passing by Rin and Len's house when she heard a loud scream coming from the house.

"That sounded like Rin! Is she okay!?" Miku said to herself in panic, not knowing that the scream was actually Rin climaxing.

However, before she could even consider trying to go investigate, the dog saw a cat in the distance and started barking before running after it at super speed, dragging poor Miku with it.

"No! Stop Oscar! Heel! Heel!"

CRASH!

"MY LEG!!!" Miku cried as a trash can lid rolled by.

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Well, that's that everyone! Short and sweet! Hope you all liked it!

Chozin out!


End file.
